1. Field of the Disclosure
The disclosure generally relates to highly porous coordination complexes defined by an inorganic center and at least two different bis(bidentate) linkers bound to that center. The complexes can be used, for example, in gas storage, separation and catalysis.
2. Brief Description of Related Technology
Due to the importance of internal surface area in various applications including gas storage, separation, and catalysis, many researchers have made efforts to discover porous materials with high surface areas. Even though thousands of microporous coordination polymers (MCPs) have been reported to date, few materials possess Brunauer-Emmett-Teller (BET) surface areas over 4000 m2/g. Those materials that do possess such high surface areas tend to require organic linkers that are not readily available at reasonable costs.
Benzene-1,4-dicarboxylic acid, also known as terephthalic acid, is used as a monomer for synthesis of various polymers (e.g., polyethylene terephthalate) and as an organic linker in microporous coordination polymers. For example, benzene-1,4-dicarboxylic acid reacts with zinc nitrate to yield Zn4O(benzene-1,4-dicarboxylate)3 (MOF-5), which has a cubic network structure in the Fm3m space group. MOF-5 has been broadly explored in the porous material field. The BET surface area of MOF-5 is approximately 3200 m2/g.
Naphthalene-2,6-dicarboxylic acid reacts with zinc nitrate to yield a material formulated as Zn4O(naphthalene-2,6-dicarboxylate)3 (IRMOF-8), the structure of which is somewhat ambiguous. It has been suggested that IRMOF-8 has an interpenetrated structure and, accordingly, the experimental BET surface area (˜1500 m2/g) of IRMOF-8 is much lower than accessible surface area derived from the theoretical non-interpenetrated crystal structure (4390 m2/g).
Generally, the prior art does not sufficiently teach or suggest to one of ordinary skill in the art how to further increase the available surface area of these microporous materials.